Target thumbv6m unsupported due to delog dependency

[thomasphillipsgb]

Using the thumbv6m toolchain when building this library you get a couple errors.

Not sure if waiting delog to support thumbv6m is the way to go.
trussed-dev/delog#9

IMO, debug info should be used for development via dev-dependency or, opt-in via feature or, compiled out for release builds or, some third option.

[elpiel]

Use this patch for delog which switches AtomicUsize with the one from the atomic-pollyfill which adds pollyfills when the platform does not support core atomic size operations.

[patch.crates-io]
delog = {git = "https://github.com/LechevSpace/delog.git", rev = "869167f7ff0630518c86f30afd215fee124d19c1"}

You can also track the PR here: trussed-dev/delog#12